Ricinoleate as oil-water demulsifier



United States Patent 3,505,307 RICINOLEATE AS OIL-WATER DEMULSIFIER Edward G. Foehr, San Rafael, Calif., assignor to Chevron Research Company, San Francisco, Calif., a corporation of Delaware No Drawing. Filed lWar. 4, 1968, Ser. No. 709,933 Int. Cl. Cm 11/00 US. Cl. 208188 3 Claims ABSTRACT OF THE DISCLOSURE Monoricinoleate esters of diand trihydroxy alkyl compounds are used as demulsifiers for lubricant oils contaminated with water.

BACKGROUND OF THE INVENTION Field of the invention Emulsification of water is a serious problem in some industrial oils where the lubricant becomes contaminated with water. For example, the rapid separation from water is a primary requirement for steel mill circulating oils. At the present time, this is generally accomplished by refinement and either clay treatment or hydrotreatment to remove emulsifying contaminants. While demulsifiers have been suggested, demulsifiers have not found use because of various deficiencies.

Description of the prior art M'onoesters of polyhydroxy compounds have found wide use as defoaming agents. See, for example, U.S. Patent Nos. 2,595,928 and 2,715,614. Partially hydrolysed turkey red oil or castor oil soap has been employed; see, van Dedem Oil & Gas 1., 65, Aug. 12, 1937.

SUMMARY OF THE INVENTION A method is provided whereby mineral lubricating oils which have emulsified undesirable amounts of water are dehydrated by the addition or presence of small amounts of the monoricinoleate ester of a polyhydroxy compound of 3 carbon atoms having from 2 to 3 hydroxyl groups. By adding or having present a small amount of the monoricinoleate ester, the oil and water phases rapidly separate and the oil phase may be withdrawn substantially free of water.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The compositions which find use in the method of this invention are the monoricinoleate ester of propane diol and triol (glycerol). The hydroxyl groups may be on adjacent carbon atoms or separated by more than 2 carbon atoms, i.e., 3 carbon atoms.

The ricinoleate ester is normally added to the lubricating oil in amounts of at least 0.05 weight percent, more usually in amounts of from about 0.075 to 0.5 weight percent, The lowest amount which is effective under the conditions to be employed will normally be used.

The hydrocarbon lubricating oils with which the ricinoleate esters are employed will generally be derived from bright stock or neutral oil having viscosities at 100 F. in the range of about 900 to 2500 Saybolt Universal seconds (SUS) and at 210 F. in the range of 80 to 160 SUS. The specific gravity of the oil will generally be in the range of about 0.88 to 0.90. The hydrocarbon oils are ordinarily derived from petroleum, although oils from other natural sources may also employ the ricinoleate ester.

In order to demonstrate the effectiveness of this method in rapidly dehydrating lubricating oils, the following test 3,505,307 Patented Apr. 7, 1970 was carried out. The test is a modification of the ASTM test for the Emulsion Characteristics of Steam-Turbine Oils, D1401.

In this modification, the equipment used is the same as in test D-l401. The bath liquid is maintained at F. and the sample and water mixture is held at this temperature for 30 minutes. In the graduate cylinder is placed 53 ml. of water and 27 ml. of sample. The mixture is stirred with the test paddle for 5 minutes at 1500 r.p.m. At the end of five minutes the paddle is stopped and raised out of the liquid.The paddle is wiped as clean as possible with a policeman, allowing the wiped emulsion to fall into the cylinder. The volume of separated water is recorded at the end of each minute for 10 to 15 minutes or until complete separation of the 53 ml. of water. The following table demonstrates the effectiveness of the use of monoricinoleate esters, specifically the glyceryl monoricinoleate with a variety of hydrocarbon lubricating oils.

TABLE I Additive Separated Water (ml) at Time in Minutes Conc., Wt. Base Oil Percent 1 2 3 4 5 6 7 8 9 10 15 1 Steel mill circulating oils comprising major amounts of high viscosity paratfinlc 011, e.g., or 230 Bright Stock or naphthenic oil or combinatrons thereof, cut back to lower viscosity with lower viscosity paraflinic oils, heig 480 Neutral oil or Heavy Turbine base stock. Parts are by weig (E) 30-480, Neutral oil; 55-185, Bright Stock; 15, naphthenic oil A.* (II) 15-480, Neutral oil; 69-185, Bright Stock; 16, naphthenic oil A. (III) 23-480, Neutral oil; 77-185, Bright Stock. (IV) 25-185, Bright Stock; 75, naphthenic oil B.* (V) 57-185, Bright Stock; 25, naphthenic 011 B; 18, parafiinio oil A. (VI) 74-230, Bright Stock; 26, parafiinic oil A. (VII)** 72-185, Bright Stock; 28-480, Neutral Oil.

*Naphthenic oil A-hydrogen treated heavy naphthenic oil.

Naphthenic oil Bacid and clay treated naphthenic oil. **Conta1ns 0.03 percent of tetrapropenyl succinic acid, a common rust preventive.

The following table uses a variety of concentrations of the glyceryl monoricinoleate and the propylene glycol monomricinoleate with a relatively viscous lubricating oil.

The base oil is 72 percent Bright Stock and 28 percent of paraflinic oil A (an acid-treated heavy grade of 480 Neutral having 99% unsulfonatable residue). The base oil blend has the following characteristics:

Viscosity at 100 F., SUS 2350 Viscosity at 210 F., SUS 131. 0 Viscosity Index 90 26. 5 Pour point, F +10 It is evident from the above results that the monoricinoleate of diand trihydroxy propanes are excellent demulsifiers, permitting the rapid dehydration of lubricating oil. The lubricating oil can be easily withdrawn from the water phase and reused without further treatment. However, it may be useful in some instances to further dehydrate the minor amounts of water still present.

As will be evident to those skilled in the art, various modifications on this invention can be made 01" followed, in the light of the foregoing disclosure and discussion, without departing from the spirit or scope of the disclosure or from the scope of the following claims.

What is claimed is:

1. A method for dehydrating lubricating oils which comprises introducing into said lubricating oil at least 0.05 weight percent and not more than 0.5 weight percent based on said lubricating oil of the monoricinoleate ester of a polyhydroxy propane having from 2 to 3 hydroxyl groups and separating the water from the oil.

2. A method according to claim 1 wherein said monoricinoleate is the ester of glycerol.

3. A method according to claim 1 wherein said mono- 4 ricinoleate ester is introduced in an amount in the range of 0.075 to 0.5 weight percent based on said lubricating oil.

References Cited UNITED STATES PATENTS 1,363,784 9/1920 Hapgood 20818O 1,617,741 2/ 1-927 Averill 2()8187 1,633,942 6/1927 Hey 208-180 FOREIGN PATENTS 173,868 9/1965 U.S.S.R.

DELBERT E. GANTZ, Primary Examiner 15 GEORGE J. CRASANAKIS, Assistant Examiner 

